Recently, as an image recording material, the materials to form color images are the mainstream. Specifically, these materials can include recording materials to be used for the inkjet method, image recording materials for thermal transfer, recording materials to be used for the electrophotographic method, halogenated silver photosensitive materials for transcription, and the like. In addition, printing inks and inks for recording pens are also actively used as one of the recording materials.
Further, in displays such as LCD (liquid crystal display) and PDP (plasma display panel), electronic parts such as CCD (charge coupled device) in photographing equipments, and the like, a color filter is used for forming color images. In them, coloring matters (dye or pigment) of 3 primary colors in so-called additive color process and subtractive color process are used for reproducing or recording fullcolor images. Actually, however, there is no coloring matter having absorption characteristics allowing reproduction of a desired color range and sufficient fastnesses in various use conditions, and improvement thereof is strongly required.
The inkjet recording method has been rapidly prevailing and further developing due to its low material cost, possibility of rapid recording, less noise in recording and also easiness of color recording. The inkjet recording method includes the continuous method of continuously flying ink droplets and the on-demand method of flying ink droplets responding to an image information signal. The discharging method includes a method of discharging ink droplets by applying pressure with piezoelectric elements; a method of discharging ink droplets by generating bubbles in ink by heat; a method by using ultrasonic waves; a method of sucking and discharging ink droplets by electrostatic force; or the like. In addition, examples of the ink suitable for inkjet recording include water-based inks, oil-based inks, solid (melting-type) inks and the like.
The requirements for the coloring matter contained in inks suitable for such inkjet recording are good solubility or dispersibility in solvents; ability of high density recording; good hue; good fastness to light, heat and active gases (oxidizing gas such as NOx and ozone, SOx and the like) in the environment, excellent durability against water and chemicals, good fixation to record-receiving materials in order not to bleed, excellent storage stability as an ink, no toxicity, and also inexpensive availability, and the like. In particular, strongly required is a cyan coloring matter which has a good cyan hue, is excellent in light fastness (durability against light), ozone fastness (durability against ozone gas) and moisture fastness (durability under high humidity) and water fastness (durability against water), and causes no bronze phenomenon (also referred to as bronzing phenomenon). Bronze phenomenon means glare phenomenon that glossy paper has a metallic luster because coloring matter is aggregated on its surface due to association and aggregation of coloring matter, malabsorption of ink to the media, or the like. This phenomenon leads to inferiority of recorded image quality in all respects such as glossiness, print quality and print density.
As a water-soluble cyan coloring matter used for inks suitable for inkjet recording, a phthalocyanine-based coloring matter and a triphenylmethane-based coloring matter are typical. The typical phthalocyanine-based coloring matter reported and used in the widest range includes phthalocyanine derivatives classified into the following A to H:    A: known phthalocyanine-based coloring matter such as Direct Blue 86, Direct Blue 87, Direct Blue 199, Acid Blue 249, Reactive Blue 71 or the like;    B: phthalocyanine-based coloring matter described in Patent Literatures 1 to 3 and the like (for example, a mixture of Cu-Pc-(SO3Na)m(SO2NH2)n: m+n=1 to 4);    C: phthalocyanine-based coloring matter described in Patent Literature 4 and the like (for example, Cu-Pc-(CO2H)m(CONR1R2)n: m+n=a number of 0 to 4);    D: phthalocyanine-based coloring matter described in Patent Literature 5 and the like (for example, Cu-Pc-(SO3H)m(SO2NR1R2)n: m+n=a number of 0 to 4, and m≠0);    E: phthalocyanine-based coloring matter described in Patent Literature 6 and the like (for example, Cu-Pc-(SO3H)l(SO2NH2)m(SO2NR1R2)n: l+m+n=a number of 0 to 4);    F: phthalocyanine-based coloring matter described in Patent Literature 7 and the like (for example, Cu-Pc-(SO2NR1R2)n: n=a number of 1 to 5);    G: phthalocyanine-based coloring matter described in Patent Literatures 8, 9 and 12 and the like (phthalocyanine compound in which the substitution position of the substituent is controlled and phthalocyanine-based coloring matter in which a substituent is introduced at the beta-position);    H: benzo pyridoporphyrazine-based coloring matter having a pyridine ring and a benzene ring, described in Patent Literatures 10, 13, 14, 15, 16 and the like.
The phthalocyanine-based coloring matter typified by Direct Blue 86 or Direct Blue 199 which are usually used widely at present has a characteristic of being excellent in light fastness compared with magenta coloring matters and yellow coloring matters which are generally known. However, the phthalocyanine-based coloring matter has a greenish hue under acidic conditions, whereby it is not very preferable as a cyan ink. Therefore, it is preferable that these coloring matters are used under neutral to alkaline conditions when used as a cyan ink. However, although the ink to be used is neutral to alkaline, the hue of a printed matter may be greatly changed when the record-receiving material to be used is an acidic paper.
In addition, there has been a problem that when the phthalocyanine-based coloring matter is used as a cyan ink, the hue of a printed matter is discolored greenish and also color fading occurs due to oxidizing gases such as nitrogen oxide gas and ozone which are often concerned nowadays as an environmental problem, whereby the print density is concurrently reduced.
On the other hand, the triphenylmethane-based coloring matter has a good hue but is very inferior in light fastness, ozone fastness and moisture fastness.
From here on, as the application field of inkjet recording is expanded and inkjet recording is widely used in articles on exhibition for advertisement and the like, there will be more opportunities for coloring matter and ink to be exposed to light and active gases in the environment, whereby the coloring matter and the ink used there will be more and more strongly required to have a good hue and to be inexpensive, and further, in particular to have a good hue and to be excellent in light fastness, fastness to active gases in the environment (oxidizing gases such as NOx, ozone and in addition SOx, and the like) and moisture fastness because they will be more often exposed to light and active gases in the environment. However, it is difficult to develop a cyan coloring matter (for example, phthalocyanine-based coloring matter) and a cyan ink which satisfy these requirements at a high level.
In the past, although phthalocyanine-based coloring matters to which fastness to active gases is imparted are disclosed in Patent Literatures 3, 8 to 12, and 14 to 16, and the like, a cyan coloring matter and a cyan ink have not yet been obtained which satisfy all the qualities such as hue, light fastness, ozone fastness, moisture fastness and no bronze phenomenon, and further which can be produced inexpensively. Therefore, the requirements of the market have not been sufficiently satisfied.    Patent Literature 1: JP S62-190273 A    Patent Literature 2: JP H7-138511 A    Patent Literature 3: JP 2002-105349 A    Patent Literature 4: JP H5-171085 A    Patent Literature 5: JP H10-140063 A    Patent Literature 6: JP H11-515048 A    Patent Literature 7: JP S59-22967 A    Patent Literature 8: JP 2000-303009 A    Patent Literature 9: JP 2002-249677 A    Patent Literature 10: JP 2003-34758 A    Patent Literature 11: JP 2002-80762 A    Patent Literature 12: WO 2004/087815 A1    Patent Literature 13: WO 2002/034844 A1    Patent Literature 14: JP 2004-75986 A    Patent Literature 14: WO 2007/091631 A1    Patent Literature 14: WO 2007/116933 A1